Detect potential file enumeration activity ASIM Web Session
Id | b3731ce1-1f04-47c4-95c2-9827408c4375 |
Rulename | Detect potential file enumeration activity (ASIM Web Session) |
Description | This detection method identifies potential cases of file enumeration activity. The query is designed to identify client sources that generate multiple requests resulting in 404 error codes |
Severity | Medium |
Tactics | Discovery CommandAndControl CredentialAccess |
Techniques | T1083 T1071 T1110 |
Kind | Scheduled |
Query frequency | 1h |
Query period | 1h |
Trigger threshold | 0 |
Trigger operator | gt |
Source Uri | https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Web Session Essentials/Analytic Rules/PotentionalFileEnumeration.yaml |
Version | 1.0.0 |
Arm template | b3731ce1-1f04-47c4-95c2-9827408c4375.json |
// HTTP response status codes indicate whether a specific HTTP request has been successfully completed.
// Please refer this for more details: https://developer.mozilla.org/en-US/docs/Web/HTTP/Status
let HTTPErrorCode=dynamic(["404"]);
let threshold = 10; // You can update this threshold to the value that suites your environment
// let FileNotFoundRequests =
_Im_WebSession (starttime=ago(1h))
| where EventResultDetails in~ (HTTPErrorCode)
// Filter the logs to include only HTTP GET requests with an HTTP status code of 404 and '/' in the URL
| where HttpRequestMethod =~ "GET" and Url contains "/"
| summarize
RequestCount = count(),
FileCount=dcount(Url),
EventStartTime=min(TimeGenerated),
EventEndTime=max(TimeGenerated),
RequestURLs = make_set(Url, 100),
DestinationIPList=make_set(DstIpAddr, 100)
by SrcIpAddr, SrcUsername, SrcHostname, DstHostname
| where RequestCount > threshold // Adjust the threshold as per your requirements
| extend Name = iif(SrcUsername contains "@", tostring(split(SrcUsername,'@',0)[0]),SrcUsername), UPNSuffix = iif(SrcUsername contains "@",tostring(split(SrcUsername,'@',1)[0]),"")
name: Detect potential file enumeration activity (ASIM Web Session)
tags:
- SchemaVersion: 0.2.6
Schema: WebSession
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Web Session Essentials/Analytic Rules/PotentionalFileEnumeration.yaml
queryPeriod: 1h
version: 1.0.0
kind: Scheduled
id: b3731ce1-1f04-47c4-95c2-9827408c4375
triggerOperator: gt
triggerThreshold: 0
relevantTechniques:
- T1083
- T1071
- T1110
customDetails:
RequestCount: RequestCount
EventEndTime: EventEndTime
RequestURLs: RequestURLs
FileCount: FileCount
DestinationIPList: DestinationIPList
EventStartTime: EventStartTime
requiredDataConnectors: []
eventGroupingSettings:
aggregationKind: AlertPerResult
severity: Medium
description: |
'This detection method identifies potential cases of file enumeration activity. The query is designed to identify client sources that generate multiple requests resulting in 404 error codes'
alertDetailsOverride:
alertDescriptionFormat: User generated multiple requests '{{RequestCount}}' that has resulted in error code '404', suggesting the possibility of file enumeration activity. It's important to investigate the source and patterns of these extensive 404 errors to identify potential security threats. Details about this error code could be found [here](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status)
alertDisplayNameFormat: User '{{SrcUsername}}' with IP '{{SrcIpAddr}}' has been observed with performing file enumeration activity
query: |
// HTTP response status codes indicate whether a specific HTTP request has been successfully completed.
// Please refer this for more details: https://developer.mozilla.org/en-US/docs/Web/HTTP/Status
let HTTPErrorCode=dynamic(["404"]);
let threshold = 10; // You can update this threshold to the value that suites your environment
// let FileNotFoundRequests =
_Im_WebSession (starttime=ago(1h))
| where EventResultDetails in~ (HTTPErrorCode)
// Filter the logs to include only HTTP GET requests with an HTTP status code of 404 and '/' in the URL
| where HttpRequestMethod =~ "GET" and Url contains "/"
| summarize
RequestCount = count(),
FileCount=dcount(Url),
EventStartTime=min(TimeGenerated),
EventEndTime=max(TimeGenerated),
RequestURLs = make_set(Url, 100),
DestinationIPList=make_set(DstIpAddr, 100)
by SrcIpAddr, SrcUsername, SrcHostname, DstHostname
| where RequestCount > threshold // Adjust the threshold as per your requirements
| extend Name = iif(SrcUsername contains "@", tostring(split(SrcUsername,'@',0)[0]),SrcUsername), UPNSuffix = iif(SrcUsername contains "@",tostring(split(SrcUsername,'@',1)[0]),"")
tactics:
- Discovery
- CommandAndControl
- CredentialAccess
entityMappings:
- entityType: IP
fieldMappings:
- columnName: SrcIpAddr
identifier: Address
- entityType: Account
fieldMappings:
- columnName: Name
identifier: Name
- columnName: UPNSuffix
identifier: UPNSuffix
- entityType: Host
fieldMappings:
- columnName: DstHostname
identifier: HostName
- entityType: Host
fieldMappings:
- columnName: SrcHostname
identifier: HostName
status: Available
queryFrequency: 1h
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"workspace": {
"type": "String"
}
},
"resources": [
{
"apiVersion": "2024-01-01-preview",
"id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/b3731ce1-1f04-47c4-95c2-9827408c4375')]",
"kind": "Scheduled",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/b3731ce1-1f04-47c4-95c2-9827408c4375')]",
"properties": {
"alertDetailsOverride": {
"alertDescriptionFormat": "User generated multiple requests '{{RequestCount}}' that has resulted in error code '404', suggesting the possibility of file enumeration activity. It's important to investigate the source and patterns of these extensive 404 errors to identify potential security threats. Details about this error code could be found [here](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status)",
"alertDisplayNameFormat": "User '{{SrcUsername}}' with IP '{{SrcIpAddr}}' has been observed with performing file enumeration activity"
},
"alertRuleTemplateName": "b3731ce1-1f04-47c4-95c2-9827408c4375",
"customDetails": {
"DestinationIPList": "DestinationIPList",
"EventEndTime": "EventEndTime",
"EventStartTime": "EventStartTime",
"FileCount": "FileCount",
"RequestCount": "RequestCount",
"RequestURLs": "RequestURLs"
},
"description": "'This detection method identifies potential cases of file enumeration activity. The query is designed to identify client sources that generate multiple requests resulting in 404 error codes'\n",
"displayName": "Detect potential file enumeration activity (ASIM Web Session)",
"enabled": true,
"entityMappings": [
{
"entityType": "IP",
"fieldMappings": [
{
"columnName": "SrcIpAddr",
"identifier": "Address"
}
]
},
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "Name",
"identifier": "Name"
},
{
"columnName": "UPNSuffix",
"identifier": "UPNSuffix"
}
]
},
{
"entityType": "Host",
"fieldMappings": [
{
"columnName": "DstHostname",
"identifier": "HostName"
}
]
},
{
"entityType": "Host",
"fieldMappings": [
{
"columnName": "SrcHostname",
"identifier": "HostName"
}
]
}
],
"eventGroupingSettings": {
"aggregationKind": "AlertPerResult"
},
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Web Session Essentials/Analytic Rules/PotentionalFileEnumeration.yaml",
"query": "// HTTP response status codes indicate whether a specific HTTP request has been successfully completed.\n// Please refer this for more details: https://developer.mozilla.org/en-US/docs/Web/HTTP/Status\nlet HTTPErrorCode=dynamic([\"404\"]);\nlet threshold = 10; // You can update this threshold to the value that suites your environment\n// let FileNotFoundRequests = \n_Im_WebSession (starttime=ago(1h))\n| where EventResultDetails in~ (HTTPErrorCode)\n// Filter the logs to include only HTTP GET requests with an HTTP status code of 404 and '/' in the URL\n| where HttpRequestMethod =~ \"GET\" and Url contains \"/\"\n| summarize\n RequestCount = count(),\n FileCount=dcount(Url),\n EventStartTime=min(TimeGenerated),\n EventEndTime=max(TimeGenerated),\n RequestURLs = make_set(Url, 100),\n DestinationIPList=make_set(DstIpAddr, 100)\n by SrcIpAddr, SrcUsername, SrcHostname, DstHostname\n| where RequestCount > threshold // Adjust the threshold as per your requirements\n| extend Name = iif(SrcUsername contains \"@\", tostring(split(SrcUsername,'@',0)[0]),SrcUsername), UPNSuffix = iif(SrcUsername contains \"@\",tostring(split(SrcUsername,'@',1)[0]),\"\")\n",
"queryFrequency": "PT1H",
"queryPeriod": "PT1H",
"severity": "Medium",
"status": "Available",
"subTechniques": [],
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"CommandAndControl",
"CredentialAccess",
"Discovery"
],
"tags": [
{
"Schema": "WebSession",
"SchemaVersion": "0.2.6"
}
],
"techniques": [
"T1071",
"T1083",
"T1110"
],
"templateVersion": "1.0.0",
"triggerOperator": "GreaterThan",
"triggerThreshold": 0
},
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
}
]
}